[dpdk-dev] [PATCH v4 3/3] vhost: optimize vhost virtqueue struct

[Maxime Coquelin]

This patch moves vhost_virtqueue struct fields in order
to both optimize packing and move hot fields on the first
cachelines.

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 lib/librte_vhost/vhost.c      |  6 ++--
 lib/librte_vhost/vhost.h      | 54 ++++++++++++++++++-----------------
 lib/librte_vhost/vhost_user.c | 23 +++++++--------
 lib/librte_vhost/virtio_net.c | 12 ++++----
 4 files changed, 48 insertions(+), 47 deletions(-)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index a8032e3ba1..04d63b2f02 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -524,7 +524,7 @@ vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq)
 	if (log_translate(dev, vq) < 0)
 		return -1;
 
-	vq->access_ok = 1;
+	vq->access_ok = true;
 
 	return 0;
 }
@@ -535,7 +535,7 @@ vring_invalidate(struct virtio_net *dev, struct vhost_virtqueue *vq)
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_wr_lock(vq);
 
-	vq->access_ok = 0;
+	vq->access_ok = false;
 	vq->desc = NULL;
 	vq->avail = NULL;
 	vq->used = NULL;
@@ -1451,7 +1451,7 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(vq->enabled == 0 || vq->avail == NULL))
+	if (unlikely(!vq->enabled || vq->avail == NULL))
 		goto out;
 
 	ret = *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 3a71dfeed9..f628714c24 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -133,7 +133,7 @@ struct vhost_virtqueue {
 		struct vring_used	*used;
 		struct vring_packed_desc_event *device_event;
 	};
-	uint32_t		size;
+	uint16_t		size;
 
 	uint16_t		last_avail_idx;
 	uint16_t		last_used_idx;
@@ -143,29 +143,12 @@ struct vhost_virtqueue {
 #define VIRTIO_INVALID_EVENTFD		(-1)
 #define VIRTIO_UNINITIALIZED_EVENTFD	(-2)
 
-	int			enabled;
-	int			access_ok;
-	int			ready;
-	int			notif_enable;
-#define VIRTIO_UNINITIALIZED_NOTIF	(-1)
+	bool			enabled;
+	bool			access_ok;
+	bool			ready;
 
 	rte_spinlock_t		access_lock;
 
-	/* Used to notify the guest (trigger interrupt) */
-	int			callfd;
-	/* Currently unused as polling mode is enabled */
-	int			kickfd;
-
-	/* Physical address of used ring, for logging */
-	uint64_t		log_guest_addr;
-
-	/* inflight share memory info */
-	union {
-		struct rte_vhost_inflight_info_split *inflight_split;
-		struct rte_vhost_inflight_info_packed *inflight_packed;
-	};
-	struct rte_vhost_resubmit_info *resubmit_inflight;
-	uint64_t		global_counter;
 
 	union {
 		struct vring_used_elem  *shadow_used_split;
@@ -176,22 +159,36 @@ struct vhost_virtqueue {
 	uint16_t		shadow_aligned_idx;
 	/* Record packed ring first dequeue desc index */
 	uint16_t		shadow_last_used_idx;
-	struct vhost_vring_addr ring_addrs;
 
-	struct batch_copy_elem	*batch_copy_elems;
 	uint16_t		batch_copy_nb_elems;
+	struct batch_copy_elem	*batch_copy_elems;
 	bool			used_wrap_counter;
 	bool			avail_wrap_counter;
 
-	struct log_cache_entry *log_cache;
-	uint16_t log_cache_nb_elem;
+	/* Physical address of used ring, for logging */
+	uint16_t		log_cache_nb_elem;
+	uint64_t		log_guest_addr;
+	struct log_cache_entry	*log_cache;
 
 	rte_rwlock_t	iotlb_lock;
 	rte_rwlock_t	iotlb_pending_lock;
 	struct rte_mempool *iotlb_pool;
 	TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
-	int				iotlb_cache_nr;
 	TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
+	int				iotlb_cache_nr;
+
+	/* Used to notify the guest (trigger interrupt) */
+	int			callfd;
+	/* Currently unused as polling mode is enabled */
+	int			kickfd;
+
+	/* inflight share memory info */
+	union {
+		struct rte_vhost_inflight_info_split *inflight_split;
+		struct rte_vhost_inflight_info_packed *inflight_packed;
+	};
+	struct rte_vhost_resubmit_info *resubmit_inflight;
+	uint64_t		global_counter;
 
 	/* operation callbacks for async dma */
 	struct rte_vhost_async_channel_ops	async_ops;
@@ -212,6 +209,11 @@ struct vhost_virtqueue {
 	bool		async_inorder;
 	bool		async_registered;
 	uint16_t	async_threshold;
+
+	int			notif_enable;
+#define VIRTIO_UNINITIALIZED_NOTIF	(-1)
+
+	struct vhost_vring_addr ring_addrs;
 } __rte_cache_aligned;
 
 /* Virtio device status as per Virtio specification */
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 4d9e76e49e..2f4f89aeac 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -406,6 +406,11 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
 	if (validate_msg_fds(msg, 0) != 0)
 		return RTE_VHOST_MSG_RESULT_ERR;
 
+	if (msg->payload.state.num > 32768) {
+		VHOST_LOG_CONFIG(ERR, "invalid virtqueue size %u\n", msg->payload.state.num);
+		return RTE_VHOST_MSG_RESULT_ERR;
+	}
+
 	vq->size = msg->payload.state.num;
 
 	/* VIRTIO 1.0, 2.4 Virtqueues says:
@@ -425,12 +430,6 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
 		}
 	}
 
-	if (vq->size > 32768) {
-		VHOST_LOG_CONFIG(ERR,
-			"invalid virtqueue size %u\n", vq->size);
-		return RTE_VHOST_MSG_RESULT_ERR;
-	}
-
 	if (vq_is_packed(dev)) {
 		if (vq->shadow_used_packed)
 			rte_free(vq->shadow_used_packed);
@@ -713,7 +712,7 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
 			return dev;
 		}
 
-		vq->access_ok = 1;
+		vq->access_ok = true;
 		return dev;
 	}
 
@@ -771,7 +770,7 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
 		vq->last_avail_idx = vq->used->idx;
 	}
 
-	vq->access_ok = 1;
+	vq->access_ok = true;
 
 	VHOST_LOG_CONFIG(DEBUG, "(%d) mapped address desc: %p\n",
 			dev->vid, vq->desc);
@@ -1658,7 +1657,7 @@ vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	vq = dev->virtqueue[file.index];
 
 	if (vq->ready) {
-		vq->ready = 0;
+		vq->ready = false;
 		vhost_user_notify_queue_state(dev, file.index, 0);
 	}
 
@@ -1918,14 +1917,14 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	 * the SET_VRING_ENABLE message.
 	 */
 	if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
-		vq->enabled = 1;
+		vq->enabled = true;
 		if (dev->notify_ops->vring_state_changed)
 			dev->notify_ops->vring_state_changed(
 				dev->vid, file.index, 1);
 	}
 
 	if (vq->ready) {
-		vq->ready = 0;
+		vq->ready = false;
 		vhost_user_notify_queue_state(dev, file.index, 0);
 	}
 
@@ -2043,7 +2042,7 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
 			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
-	int enable = (int)msg->payload.state.num;
+	bool enable = !!msg->payload.state.num;
 	int index = (int)msg->payload.state.index;
 
 	if (validate_msg_fds(msg, 0) != 0)
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 583bf379c6..3d8e29df09 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1396,13 +1396,13 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(vq->enabled == 0))
+	if (unlikely(!vq->enabled))
 		goto out_access_unlock;
 
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_rd_lock(vq);
 
-	if (unlikely(vq->access_ok == 0))
+	if (unlikely(!vq->access_ok))
 		if (unlikely(vring_translate(dev, vq) < 0))
 			goto out;
 
@@ -1753,13 +1753,13 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(vq->enabled == 0 || !vq->async_registered))
+	if (unlikely(!vq->enabled || !vq->async_registered))
 		goto out_access_unlock;
 
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_rd_lock(vq);
 
-	if (unlikely(vq->access_ok == 0))
+	if (unlikely(!vq->access_ok))
 		if (unlikely(vring_translate(dev, vq) < 0))
 			goto out;
 
@@ -2518,7 +2518,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 	if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
 		return 0;
 
-	if (unlikely(vq->enabled == 0)) {
+	if (unlikely(!vq->enabled)) {
 		count = 0;
 		goto out_access_unlock;
 	}
@@ -2526,7 +2526,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_rd_lock(vq);
 
-	if (unlikely(vq->access_ok == 0))
+	if (unlikely(!vq->access_ok))
 		if (unlikely(vring_translate(dev, vq) < 0)) {
 			count = 0;
 			goto out;
-- 
2.30.2